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Removal characteristics and kinetic analysis of an aerobic vapor-phase bioreactor for hydrophobic alpha-pinene

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Journal of environmental sciences 2012年第8期24卷 1439-1448页

作者： Yifeng Jiang Shanshan Li Zhuowei cheng Runye Zhu Jianmeng chen College of Biological and environmental Engineering Zhejiang University of Technology Hangzhou 310032 China Engineering Research Center of the Ministry of Education for Bioconversion and Biopurification Zhefiang University of Technology Hangzhou 310032 China

Biofiltration is considered an effective method to control volatile organic compounds （VOCs） pollution. This study was conducted to evaluate the potential use of a bacterial biofilter packed with wood chips and peat for the removal of hydrophobic α-pinene. When inoculated with two pure degraders and adapted activated sludge, a removal efficiency （RE） of more than 95% was achieved after a start- up period of 11 days. The maximum elimination capacity （EC） of 50 g/（m^***） with RE of 94% was obtained at empty bed retention time （EBRT） of 102.sec. When higher α-pinene concentrations and shorter EBRTs were applied, the REs and ECs decreased significantly due to mass-transfer and biological reaction limitations. As deduced from the experimental results, approximately 74% of ct-pinene were completely mineralized by the consortiums and the biomass yield was 0.60 g biomass/g α-pinene. Sequence analysis of the selected bands excised from denaturing gradient gel electrophoresis revealed that the inoculated pure cultures could be present during the whole operation, and others were closely related to bacteria being able to degrade hydrocarbons. The kinetic results demonstrated that the whole biofiltration for α-pinene was diffusion-limit controlled owing to its hydrophobic characteristics. These findings indicated that this bacterial biofiltration is a promising technology for the remediation of hydrophobic industrial waste gases containing ct-pinene.

关键词： biofilters gaseous α-pinene removal characteristics microbial community kinetic parameters

Plant coexistence can enhance phytoextraction of cadmium by tobacco (Nicotiana tabacum L.) in contaminated soil

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Journal of environmental sciences 2011年第3期23卷 453-460页

作者： Ling Liu Yuefang Li Jianjun Tang Liangliang Hu Xin chen College of Life sciences Zhejiang University Hangzhou 310058 China College of Agriculture Henan University of Science and Technology Luoyang 471003 China

A mesocosm experiment was conducted to investigate whether plant coexistence affects cadmium （Cd） uptake by plant in contaminated soil. Tobacco （Nicotiana tabacum L. var. K32.） and Japanese clover （Kummerowia striata （Thunb.） Schindl.） were used. Cadmium was applied as ***2. in solution at three levels （0, 1, and 3 mg/kg soil） to simulate an unpolluted soil and soils that were slightly and moderately polluted with Cd. Tobacco （crop）, Japanese clover （non-crop）, and their combination were grown under each Cd treatment. Compared to monoculture and under all Cd treatments, co-planting with Japanese clover did not affect tobacco biomass but significantly increased Cd concentration in all tobacco tissues and enhanced Cd accumulation in tobacco shoots and roots. Compared to monoculture, co-planting reduced soil pH and increased Cd bioavailability. For tobacco, co-planting with Japanese clover increased the Cd bioconcentration factor （BCF） in Cd contaminated soil. Japanese clover also accumulated substantial quantities of Cd in shoots and roots. Thus, total Cd uptake by the plants was much greater with co-planting than with monoculture. The results suggested that phytoextraction can be effectively increased through tobacco co-planting with Japanese clover in mildly Cd-contaminated soil.

关键词： plant coexistence phytoextraction cadmium tobacco Japanese clover

Advantages of intermittently aerated SBR over conventional SBR on nitrogen removal for the treatment of digested piggery wastewater

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Frontiers of environmental science & Engineering 2017年第3期11卷 131-140页

作者： Xiaoyan Song Rui Liu Lujun chen Baogang Dong Tomoki Kawagishi zhejiang Provincial Key Laboratory of Water science and Technology Department of Environment in Yangtze Delta Region Institute of Tsinghua University-Zhejiang Jiaxing 314006 China School of Environment Tsinghua University Beijing 100084 China Aqua Development Center Mitsubishi Rayon Co. Ltd. Toyohashi 4408601 Japan

An intermittently aerated sequencing batch reactor （IASBR） and a traditional sequencing batch reactor （SBR） were parallelly constructed to treat digested piggery wastewater, which was in high NH4＋ -N concentration but in a low COD/TN ratio. Their pollutant removal perfonnance was compared under COD/TN ratios of 1.6-3.4 d and hydraulic retention times of 5 3 d. The results showed that the IASBR removed TN, NH4＋-N and TOC more efficiently than the SBR. The average removal rates of TN, NH4＋-N and TOC were 83.1%, 96.5%, and 89.0%, respectively, in the IASBR, significantly higher than the corresponding values of 74.8%, 82.0%, and 86.2.. in the SBR. Mass balance of organic carbon revealed that the higher TN removal in the IASBR might be attributed to its efficient utilization of the organic carbon for denitrification, since that 48.7%- 52.2. of COD was used for denitrification in the IASBR, higher than the corresponding proportion of 43.1%-47.4% in the SBR. A prc-anoxic process in the IASBR would enhance the ammonium oxidation while restrict the nitrite oxidation. Anoxic duration of 40-80 min should be beneficial for achieving stable nitritation.

关键词： Anoxic stress Carbon source Digested piggery wastewater Intermittently aerated SBR (IASBR)Total nitrogen

Comparative study on microbial community in intermittently aerated sequencing batch reactors （SBR） and a traditional SBR treating digested piggery wastewater

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Frontiers of environmental science & Engineering 2017年第3期11卷 97-106页

作者： Xiaolin Sheng Rui Liu Xiaoyan Song Lujun chen Kawagishi Tomoki zhejiang Provincial Key Laboratory of Water science and Technology Department of Environment in Yangtze Delta Region Institute of Tsinghua University Zhejiang Jiaxing 314006 China School of Environment Tsinghua University Beijing 100084 China Aqua Development Center Mitsubishi Rayon Co. Ltd. Toyohashi 4408601 Japan

A traditional sequencing batch reactor （SBR） and two intermittently aerated sequencing batch reactors （IASBRs） were parallelly operated for treating digested piggery wastewater. Their microbial communities were analyzed, and the nitrogen removal performance was compared during the long term run. IASBRs demonstrated higher removal rates of total nitrogen （TN） and ammonium nitrogen （NH4＋ -N） than the SBR, and also demonstrated higher resistance against TN shock load. It was found that the more switch times between aerobic/anoxic in an IASBR, the higher the removal rates of TN and NH4＋ N. All the reactors were predominated by Thauera, Nitrosomonas and Nitrobacter, which were considered to be species of denitrifiers, ammonium oxidizing bacteria （AOB） and nitrite oxidizing bacteria （NOB）, respectively. However, the abundance and diversity was of great difference. Compared with SBR, IASBRs achieved higher abundance of denitrification related bacteria. IASBR 1# with four aerobic/anoxic switch times was detected with 2..63% of Thauera, higher than that in IASBR 2. with two aerobic/anoxic switch times （l 1.57% of Thauera）, and much higher than that in the SBR （only 6.19% of Thauera）. IASBR 2. had the highest percentage of AOB, while 1ASBR 1# had the lowest percentage. The denitrifiers abundance was significantly positive correlated with the TN removal rate. However, the NH4＋ N removal rate showed no significant correlation with the AOB abundance, but might relate to the AOB activity which was influenced by the average free ammonium （FA） concentration. Nitrobacter was the only NOB genus detectable in all reactors, and were less than 0.03%.

关键词： Digested piggery wastewater Intermittent aeration aeration Microbial community Partial nitrification^lenitrification processSequencing batch reactor (SBR)

Effects of field application of phosphate fertilizers on the availability and uptake of lead, zinc and cadmium by cabbage (Brassica chinensis L.) in a mining tailing contaminated soil

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Journal of environmental sciences 2008年第9期20卷 1109-1117页

作者： WANG Biling XIE Zhengmiao chen Jianjun JIANG Juntao SU Qiufeng College of environmental science and Natural Resources Zhejiang University Hangzhou 310029 China department of environmental{2. and Engineering Hangzhou Dianzi University Hangzhou 310018 China

A field trial was conducted to evaluate the reduction of bioavailability of heavy metals including lead (Pb), zinc (Zn) and cadmium (Cd) in a soil contaminated by mining tailings in Shaoxing, zhejiang, china. Three commercial phosphate (P) fertilizers including phosphate rock (PR), calcium magnesium phosphate (CMP), and single superphosphate (SSP) were applied to the plot at three P application rates, 50, 300, and 500 g/m2.with 9 treatments and control (CK). Plants, water soluble and exchangeable (WE) extra...

关键词： bioavailability Brassica chinensis L. (cabbage) cadmium lead phosphorus fertilizer zinc

Effect of particle size on the transformation kinetics of flue gas desulfurization gypsum to α-calcium sulfate hemihydrate under hydrothermal conditions

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Particuology 2018年第5期16卷 98-104页

作者： Hailu Fu Caiyun Jia Qiaoshan chen Xueting Cao Xiaomin Zhang department of environmental Engineering ChinaJiliang UniversityHangzhou 310018China department of environmental Engineering Zhejiang UnzversityHangzhou 310058China

The effect of particle size on the transformation kinetics of flue gas desulfurization (FGD)gypsum to α-calcium sulfate hemihydrate (α-HH)in calcium chloride (CaCl2.solutions was investigated to better guide value-added FGD gypsum *** samples from different sources were sieved into several size groups,and their transformation rates were *** results showed that using FGD gypsum with a smaller particle size accelerated the transformation to α-*** size effect accelerated nucleation kinetics of α-HH rather than its crystal growth rate (that is,the thermodynamic driving force for the transformation changed little with particle size variation).Analysis using a kinetics model revealed that a smaller gypsum particle size lowered the overall activation energy barrier for the *** is because the smaller gypsum particles had a larger relative specific surface area and thus provided more nucleation sites and crystalline defects to promote α-HH nucleation.A smaller particle size of FGD gypsum also gave a higher yield of fine α-HH particles because of the increased incidence of primary and secondary nucleation coupled with *** paper indicates the transformation of FGD gypsum into α-HH could be effectively promoted by regulating FGD gypsum particle size.

关键词： Particle size Gypsum Phase transformation Crystallization

Kinetic analysis and bacterium metabolization of α-pinene by a novel identified Pseudomonas ***

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Journal of environmental sciences 2012年第10期24卷 1806-1815页

作者： Zhuowei cheng Pengfei Sun Yifeng Jiang Lili Zhang Jianmeng chen Engineering Research Center of the Ministry of Education for Bioconversion and Biopurificationm zhejiang university of Technology Hangzhou 310032 China. College of Biological and environmental Engineering Zhejiang University of Technology Hangzhou 310032 China

Biodegradation has become a popular alternative remediation technology for its economic and ecological advantages. An aerobic bacterium （strain ZW） capable of degrading α-pinene was isolated from a biofilter by a selective enrichment. Based on the 16S rRNA gene analysis and physiochemical properties, this strain was identified as Pseudomonas veronii. Under the optimized condition achieved by the response surface methodology （RSM）, as well as pH 6.82. temperature 2..3℃ and NaC1 concentration 1.36%, almost 100% α-pinene could be removed within 45 hr. Enzymatic biodegradation by the crude intracellular enzyme could be described well by the Michaelis-Menten model in which the maximum degradation rate Vraax and the half-saturation constant Km were calculated to be 0.431 mmol/（***） and 0.169 mmol/L, respectively. Activity assay of catechol suggested that the strain ZW possessed a catechol- 1,2.dioxygenase and could decompose benzene-ring through ortho ring cleavage. Based on the identified intermediates by GC/MS, a new metabolic pathway was proposed, in which the final metabolites were some simpler organic and inorganic compounds. The present work demonstrated that the strain ZW would have a great application prospect for the remediation of α-pinene-contaminated environment.

关键词： Pseudomonas veronii ct-pinene growth conditions kinetics analysis metabolic pathway

Answer to comments on “Fabrication and photovoltaic conversion enhancement of graphene/n-Si Schottky barrier solar cells by electrophoretic deposition”

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Journal of Semiconductors 2017年第4期38卷 63-67页

作者： Leifeng chen Hong He College of Materials and environmental Engineering Hangzhou Dianzi University State Key Laboratory of Silicon Materials and department of Materials science and Engineering Zhejiang University

Here,we reply to comments by Valentic et *** our paper published in Electrochimica Acta（2.14,130：2.9）.They commented that Au nanoparticles played the dominant role on the whole cell＇s performances in our improved graphene/Si solar *** argued that our devices are Au-doped graphene/n-Si Schottky barrier devices,not Au nanoparticles（film）/n-Si Schottky barrier *** the doping process,most of the Au nanopatricles covered the surfaces of the *** barriers between doped graphene and n-Si dominate the total cells *** doping,by adjusting and tailoring the Fermi level of the graphene,the Fermi level of n-Si can be shifted down in the graphene/Si Schottky barrier *** also argued that the instability of our devices were related to variation in series resistance reduced at the beginning due to slightly lowered Fermi level and increased at the end by the serf-compensation by deep in-diffusion of Au *** for our fabricated devices,we know that an oxide layer covered the Si surface,which makes it difficult for the Au ions to diffuse into the Si layer,due to the continuous growth of SiO2.layer on the Si surface which resulted in series resistance decreasing at first and increasing in the end.

关键词： solar cell graphene silicon chemical doping Au nanoparticles

Long-term variation and evaluation of air quality across Hong Kong

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Journal of environmental sciences 2023年第5期127卷 284-294页

作者： Yan Tan Shuwen Han Yi chen Zhongbiao Wu Shun-cheng Lee School of environmental and Municipal Engineering Qingdao University of Technology department of Civil and environmental Engineering The Hong Kong Polytechnic University Division of Environment and Sustainability The Hong Kong University of Science and Technology Key Laboratory of Environment Remediation and Ecological Health Ministry of Education College of Environmental and Resource Sciences Zhejiang University

Study of Air Quality Objectives (AQOs) and long-term changes of air pollution plays a decisive role in formulating and re?ning pollution control *** this study,10-year variations of six major air pollutants were analyzed at seven monitoring sites in Hong *** continuous decrease of annual averaged concentrations of NO2.SO2.CO,PM2.5and PM10and numbers of days with severe pollution conditions validated the ef?ciency of the series of air pollution control schemes implemented by the Hong Kong ***,there is still a big gap to meet the ultimate targets described by the World Health ***,the concentration of O3at roadside and urban stations increased by 135%±2.%and37%±18%from 2.11 to 2.2.,respectively,meanwhile the highest 8 hr averaged O3concentration was observed as 2.4μg/m3at background station in 2.2.,which pointed out the increasing ozone pollution in Hong *** was a great decrease in the annual times of air quality health index (AQHI) laying in“high”,“very high”and“serious”categories from2.11 to 2.2. with the decrease rate of 89.70%,91.30%and 89.74%at roadside stations,and79.03%,95.98%and 72.73%at urban stations,***,the number of days categorized as“high”or above at roadside station was twice more than that in the urban station during the past ten ***,more policies and attentions should be given to the roadside air quality and its adverse health effect to pedestrians on street.

关键词： Long-term variation Roadside Hong Kong air quality Air Quality Objectives (AQO) Air quality health index (AQHI)